Exploring Mo-ZnO@NF for hydrogen generation and methylene blue remediation: sunlight-driven catalysis

In this study, we elucidate the synthesis and characterization of molybdenum (Mo) doped zinc oxide (ZnO) nanoflowers (Mo-ZnO@NF) fabricated via a hydrothermal approach, showcasing their potential application in hydrogen generation and dye degradation. The successful synthesis of these nanoflowers is achieved through the deliberate incorporation of Mo ions into the ZnO lattice, yielding a distinctive hierarchical flower-like morphology. Comprehensive structural, morphological, and optical analyses are conducted employing a suite of analytical techniques, encompassing XRD, Raman, FESEM, and UV-Visible spectroscopy. XRD analysis confirms the retention of the hexagonal wurtzite crystal structure, accompanied by discernible peak shifts indicative of Mo ion integration. FESEM imaging further elucidates the flower-like architecture of Mo-ZnO, underscoring the intricate morphological features. Photocatalytic assessment reveals the remarkable efficacy of Mo-ZnO@NF, as evidenced by an unprecedented hydrogen evolution rate of 2024 mmol/h/g and 97% Methylene Blue (MB) dye degradation within a mere 40-minute timeframe. Furthermore, a comparative investigation between pristine ZnO and varying Mo doping concentrations (ranging from 1% to 5%) underscores the optimal doping concentration of 1% Mo in ZnO. This concentration threshold is shown to engender superior photocatalytic performance, potentially attributed to enhanced charge carrier separation and increased surface area conducive to catalytic reactions. Overall, this study not only advances our understanding of Mo-ZnO@NF nanostructures but also elucidates key insights into optimizing their photocatalytic efficacy for diverse environmental remediation applications

A Cryptographic Solution to the Predefind Bound of Ciphertext Classes in KAC

In Cloud Computingsecure data sharing is an important functionality. Cloud computing is the storing of data online which is accessible from multiple and connected resources. It is the fastest growing field in computer world which serves various services to users. Using Cloud Storage, users can remotely store their data and enjoy the on-demand high quality applications and services. This paper attempts to show how data is shared among cloud users securely, efficiently, and flexibly. On cloud anyone can share data as much they want to i.e. only selected content can be shared. With cryptography users can share the data to others in safe way. So that user encrypts data and upload it on cloud server. The proposed algorithm uses a new cryptosystem that is called as Key Aggregate Cryptosystem (KAC)[1] which generates a single key for multiple files. In particular, it uses a public key encryption which releases aggregate key for set of secret keys. With this aggregate key others can decrypt ciphertext set and remaining encrypted files outside the set are remains confidential

Ferrocenylethenyl-substituted oxadiazoles with phenolic and nitro anchors as sensitizers in dye sensitized solar cells

Three new ferrocenyl oxadiazoles, viz. (E)-2-(4-hydroxyphenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D2), (E)-2-(4-nitrophenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D3) and (E)-3-(4-nitrophenyl)-5-[5-(2-ferroceneylethen-1-yl)-1,3,4-oxadiazol-2-yl]-1,2,4-oxadiazole (D4) derived from (E)-3-ferrocenylacrylic acid (D1) having phenolic or nitro anchors, have been synthesized and characterized using microanalyses and relevant spectroscopic techniques. UV-Vis spectroscopic studies indicate that with respect to ferrocene, the electronic absorption bands of the new compounds are bathochromically shifted up to 600 nm with a concomitant enhancement in their intensities. All four compounds have been used as photosensitizers in TiO 2 -based dye-sensitized solar cells (DSSCs). The photovoltaic performances and charge transport properties (EIS spectra) of these compounds were studied to appraise their dye performance. All four compounds displayed good photovoltaic performances. However, compounds D2 and D4 displayed superior performance, which might be due to the better electronic communication between the ferrocenyl moiety and the six membered aromatic ring with their -OH/NO 2 anchors having five membered oxadiazole spacers, as well as the high dye loading of these compounds on the TiO 2 surface, which suppresses charge recombination, prolongs electron lifetime, and decreases the total resistance of DSSCs. The assembly fabricated using D4 performed better with an overall conversion efficiency η of 4.70%, J sc of 10.33 mA cm -2 and V oc of -0.712 V. </p

Indium-doped ZnOas efficient photosensitive material for sunlight driven hydrogen generation and DSSC applications: integrated experimental and computational approach

Electricity generation using simple and cheap dye-sensitized solar cells and photocatalytic water splitting to produce future fuel, hydrogen, directly under natural sunlight fascinated the researchers worldwide. Herein, synthesis of indium-doped wurtzite ZnO nanostructures with varying molar percentage of indium from 0.25 to 3.0% with concomitant characterization indicating wurtzite structure is reported. The shift of (002) reflection plane to higher 2θ degree with increase in indium-doping thus is a clear evidence of doping of indium in zinc oxide nanoparticles. Surface morphological as well as microstructural studies of In@ZnO exhibited generation of ZnO nanoparticles and nanoplates of diameter 10–30 nm. The structures have been correlated well using computational density functional (DFT) studies. Diffuse reflectance spectroscopy depicted the extended absorbance of these materials in the visible region. Hence, the photocatalytic activity towards hydrogen generation from water under natural sunlight as well as efficient DSSC fabrication of these newly synthesized materials has been demonstrated. In-doped ZnO exhibited enhanced photocatalytic activity towards hydrogen evolution (2465 μmol/h/g) via water splitting under natural sunlight. DSSC fabricated using 2% In-doped ZnO exhibited an efficiency of 3.46% which is higher than other reported In-doped ZnO based DSSCs

Low Temperature Deposition of TiO2 Thin Films through Atmospheric Pressure Plasma Jet Processing

Titanium dioxide (TiO2) has been widely used as a catalyst material in different applications such as photocatalysis, solar cells, supercapacitor, and hydrogen production, due to its better chemical stability, high redox potential, wide band gap, and eco-friendly nature. In this work TiO2 thin films have been deposited onto both glass and silicon substrates by the atmospheric pressure plasma jet (APPJ) technique. The structure and morphological properties of TiO2 thin films are studied using different characterization techniques like X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and field emission scanning electron microscopy. XRD study reveals the bronze-phase of TiO2. The XPS study shows the presence of Ti, O, C, and N elements. The FE-SEM study shows the substrate surface is well covered with a nearly round shaped grain of different size. The optical study shows that all the deposited TiO2 thin films exhibit strong absorption in the ultraviolet region. The oleic acid photocatalytic decomposition study demonstrates that the water contact angle decreased from 80.22 to 27.20&deg; under ultraviolet illumination using a TiO2 photocatalyst

Ferrocenylethenyl-substituted oxadiazoles with phenolic and nitro anchors as sensitizers in dye sensitized solar cells

Three new ferrocenyl oxadiazoles, viz. (E)-2-(4-hydroxyphenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D2), (E)-2-(4-nitrophenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D3) and (E)-3-(4-nitrophenyl)-5-[5-(2-ferroceneylethen-1-yl)-1,3,4-oxadiazol-2-yl]-1,2,4-oxadiazole (D4) derived from (E)-3-ferrocenylacrylic acid (D1) having phenolic or nitro anchors, have been synthesized and characterized using microanalyses and relevant spectroscopic techniques. UV-Vis spectroscopic studies indicate that with respect to ferrocene, the electronic absorption bands of the new compounds are bathochromically shifted up to 600 nm with a concomitant enhancement in their intensities. All four compounds have been used as photosensitizers in TiO 2 -based dye-sensitized solar cells (DSSCs). The photovoltaic performances and charge transport properties (EIS spectra) of these compounds were studied to appraise their dye performance. All four compounds displayed good photovoltaic performances. However, compounds D2 and D4 displayed superior performance, which might be due to the better electronic communication between the ferrocenyl moiety and the six membered aromatic ring with their -OH/NO 2 anchors having five membered oxadiazole spacers, as well as the high dye loading of these compounds on the TiO 2 surface, which suppresses charge recombination, prolongs electron lifetime, and decreases the total resistance of DSSCs. The assembly fabricated using D4 performed better with an overall conversion efficiency η of 4.70%, J sc of 10.33 mA cm -2 and V oc of -0.712 V. </p